VS Motorsports converts a E46 M3 SMG transmission to manual as a solution rather than buying a new hydraulic pump

The E46 M3 SMG (sequential manual gearbox) is basically the exact same thing as the manual transmission except with a hydraulically actuated shifting mechanism. The hydraulic pump can fail and VS Motorsports states the replacement cost is $2500 (a bit high) from BMW. Regardless, many people have wondered how much it would cost to simply switch an SMG to manual as well as how difficult it would be. VS Motorsports answers the latter below with an SMG to manual swap.

"If you are looking to get the manual swap done, we finished the swap for our good customer and now have the information that many people could not find. We now know without a doubt this can be done, what parts are needed, and what software to get. Having the manual will give you the piece of mind for no more guessing what the problems are, no more replacing smg relays, hydraulic pumps. accumulators, re setting smg adaptations, and worry about smg issues.

What you will need.

-You will need either a manual transmission or just the bell housing off a manual car. (Some people have machined the smg bell housing and inserted the necessary parts from the manual cars but we have not done this and you could run the risk of machining the bell housing wrong and then you are stuck. Then still have to buy a new bell housing or transmission.)

Transmission with the bell housing off

Inside the SMG Bell Housing:

Install the necessary parts missing on a SMG car that a Manual has. We have the list already and know what needs to be ordered. Some of these parts can be upgraded to aftermarket such as the shifter (short shifter), Clutch slave cylinder line, shift boot, etc. Also this is the perfect time to replace the clutch, upgrade clutch or change flywheel.

Manual Shift lever installed.

Updated Software to have the car recognize that it is now a manual. This will turn off the gear indicator and the SMG fault code lights.

Picture of the SMG indictors off.

Lastly you will lose your neutral safety switch and cruise control. Only way to make them work is for us to build a harness to the DME since there is no harness to purchase from BMW. This would take a lot of time for us to do on the first car. So instead of doing that we can delete the neutral safety switch. By doing this it means the car will not have cruise control, and the car could potential start in gear. You will need to take extra precaution to make sure not start the car in gear or it can jump forward/backwards potential hitting a car in front or behind you. "

So the limitation for the E46 SMG is the hydraulic pump? Can that trans hold a lot of power otherwise?

transmission is the same. as far as the pump i dunno.
im on 17k boosted with my smg and others have thousands more miles than i but it appears to be luck of the draw. i know a few boosted guys get issues right out of the gate with the smg system.

fwiw - i bought a complete smg unit prior to turbo with this sort of issue in mind.

VS Motorsports does most of the work on my car and I can say they are have a very knowledgable staff. The best part is that they daily drive and competitively race E46 M3s. This definitely made my search for another used E46 M3 a little easier. I often find very clean SMG E46s but I just really dislike the way it shifts. It's good knowing that there's still an alternative route.

VS Motorsports does most of the work on my car and I can say they are have a very knowledgable staff. The best part is that they daily drive and competitively race E46 M3s. This definitely made my search for another used E46 M3 a little easier. I often find very clean SMG E46s but I just really dislike the way it shifts. It's good knowing that there's still an alternative route.

It is just difficult to find a buyer for a vehicle that has been converted. One call to a dealer and they'll know what options it came with. So really you need to do it right and document the process, so you can show a buyer that the conversion was done properly.

Originally Posted by Sticky

How difficult was it to machine the bellhousing and was that cheaper than buying a manual one?

Machining the bellhousing was not difficult, just not precise. I have some pictures here that show what needs to be done.

To be clear, this is the only difference between an SMG and a manual transmission. The purpose of these additional parts on the manual transmission is to provide gearshift centering. Without these detents, the shifter could flop around between the 1-2 gate and the 5-6 gate with no resistance, and it would be extremely easy to accidentally shift into reverse.

To do the conversion, simply bore those two holes into the bellhousing to install the detents. There are marks in the bellhousing casting that can be a rough guide. These holes will need grooves for snap rings on the outside. Also, the dowel that the spring rests on must be fabricated and installed, as it is not available for purchase.

It is just difficult to find a buyer for a vehicle that has been converted. One call to a dealer and they'll know what options it came with. So really you need to do it right and document the process, so you can show a buyer that the conversion was done properly.

Machining the bellhousing was not difficult, just not precise. I have some pictures here that show what needs to be done.

To be clear, this is the only difference between an SMG and a manual transmission. The purpose of these additional parts on the manual transmission is to provide gearshift centering. Without these detents, the shifter could flop around between the 1-2 gate and the 5-6 gate with no resistance, and it would be extremely easy to accidentally shift into reverse.

To do the conversion, simply bore those two holes into the bellhousing to install the detents. There are marks in the bellhousing casting that can be a rough guide. These holes will need grooves for snap rings on the outside. Also, the dowel that the spring rests on must be fabricated and installed, as it is not available for purchase.